SOO On Gravelhj and Calculous Cujicrethm. 



jn the acidulous tartarite of potash, chiefly prevails in the 

 wines and beverage of those countries most subject to these 

 complaints. 



Experiment \l\. 



To four ounces of healthy adult urine were added some 

 drops only of pure tartarous acid. To the same quaatity 

 cue drachui of acetous acid, which brought them nearly to 

 the same standard of acidity; a circumstance always at- 

 tended to in the comparntive trials with difl^'erent acids. In 

 that with the tartarous acid the crystals were not only larger 

 and diarker coloured, but exceeded in quantity any thing 

 before observed. In that with the acetous acid, a nuich 

 smaller proportion of minute crystals took place. 



Experimejit VIII. 



To four ounces of urine were added two drachms of a 

 filtevcd solution of acidulous tartarite of potash of the tem- 

 perature 55 degrees. The usual separation and crystalliza- 

 tion took place in large proportion : the crystals, however, 

 much sniallcr, and less coloured, than those with the un- 

 con)biiied tartarous acid. The two last experiments, frer 

 qucutly repeated^ presented the same results. 

 Experimevt IX. 



The result of the above experiments having led to som& 

 tloubt 3S to the good effects of the carbonic acid gas, so 

 much, at one time, recommended by doctors Percival and 

 Saunders, previous to its more modern alkaline combina-. 

 tion in our mcphitic as well as super -aerated soda waters : 



Info the middle part of Noolh's apparatus were intro- 

 (^uced four pounds of fresh rendered healthy urine, and ex ■ 

 posed to a stream of carbonic acid gas. Alter a few hour^ 

 a copious and beautiful precipitation of uric crystals took 

 placCj (notwithstanding the constant agitation from the 

 transmission of the gaseous bubbles,) larger than any I 

 before observed, that from the tartarous acid excepted. In 

 a standard quantity, no distinct crystallization, even after 

 two days. A repetition of the same experiment afforded 

 btmilar results. 



Experiment X. 



Finding the carbonic acid gas productive of similar ef- 

 fects with the other acids hitherto examined, it was natural 

 to inquire how far its combination with the portion of al- 

 kaline matter contained in our mephitic and soda waters, 

 so highly surcharged with it, may prevent a separation of 

 this uric acid. 



Half 



